A methodology has been developed for the non-invasive exploration and diagnosis of brain function in children with learning disabilities. Topograhic and statistical analysis of brain electrical activity are the base of this methodology. We have used these techniques to demonstrate functionally significant regional differences in the spectrally analyzed electroencephalographic and evoked potential data from 10 year old dyslexics. Measures from the topographic maps were 80-90% successful in prospective diagnostic tests. We have confirmed these findings on a larger population of 10 year olds. A pilot study has shown similar results in six year old children at risk for reading disability. We propose a combined neurophysiological and neuropsychological/behavioral investigation of kingergarten children who will be re-investigated at the 2nd grade point. We will (1) search, at each age point, for correlations between neuropsychological/behavioral and neurophysical data , (2) investigate the consistency in functioning of children as they move from one point to the next, (3) evaluate by use of the serial studies the question whether dyslexia and other school problems represent a difference in brain organization or an immaturity in brain development, (4) search the neurophysiological data for clinicaly meaningful patterns, (5) develop diagnostic rules to predict 2nd grade outcome from preschool measures, and (6) develop and test a new behavioral assessment. We anticipate that combined neurophysiological and neuropsychological measures will improve early and specific detection of learning disabled children, a prerequisite in the optimization of remedial measures and, therewith, the economical use of resources. Furthermore, we anticipate that correlations between our two data types will expand the basic understanding of pathophysiological mechanisms in these disorders and will elucidate the development of brain-behavior relationships.